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Photoionization of the C‐1C‐4 monosubstituted alkyl benzenes: Thermochemistry of [C 7 H 7 ] + and [C 8 H 9 ] + formation
Author(s) -
McLoughlin R. G.,
Morrison J. D.,
Traeger J. C.
Publication year - 1979
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210140209
Subject(s) - photoionization , thermochemistry , fragmentation (computing) , chemistry , standard enthalpy of formation , alkyl , ion , medicinal chemistry , photochemistry , organic chemistry , ionization , computer science , operating system
The appearance energies for the [C 7 H 7 ] + and [C 8 H 9 ] + fragment ions produced in the fragmentation of the C‐1C‐4 monosubstituted alkyl benzenes have been measured by photon impact. The mean heat of formation calculated for [C 7 H 7 ] + is 205.3 ± 1.9 kcal mol −1 which is consistent with a threshold tropylium structure. For [C 8 H 9 ] + the mean heat of formation is calculated to be 199.2 ± 1.3 kcal mol −1 which can be equated with either a methyl tropylium or α‐phenylethyl structure at threshold. Some evidence is provided for the existence of the α‐phenylethyl ion.